Adjusting the valve clearance of six-cylinder diesel engine
When the intake valve and exhaust valve overlap, this is the exhaust top dead center of cylinder 6. At this time, cylinder 1 is at compression top dead center. 1 cylinder's intake and exhaust valves, cylinder 2' s intake valve, cylinder 3' s exhaust valve, cylinder 4' s intake valve and cylinder 5' s exhaust valve can be adjusted, and these valves are absolutely closed.
Then turn the crankshaft 360 degrees, find the compression top dead center of cylinder 6 according to this method, and adjust other valves.
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Diesel engine is an engine that burns diesel oil to obtain energy release.
It was invented by German inventor Rudolf Dissel in 1892. In memory of this inventor, the Diesel engine is represented by his surname diesel, which is also called diesel engine.
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The advantages of diesel engine are large torque and good economic performance. The working process of diesel engine has many similarities with that of gasoline engine, and each working cycle has to go through four strokes: intake, compression, work and exhaust.
However, because the fuel used by diesel engine is diesel, its viscosity is higher than that of gasoline and it is not easy to evaporate, but its auto-ignition temperature is lower than that of gasoline. Therefore, the formation and ignition mode of combustible mixture is different from gasoline. The main difference is that the mixture in the cylinder of diesel engine is compression ignition, not ignition.
When the diesel engine is working, air enters the cylinder. When the air in the cylinder is compressed to the end, the temperature can reach 500-700℃ and the pressure can reach 40-50 atmospheres.
When the piston approaches the top dead center, the fuel nozzle of the oil supply system injects the fuel into the combustion chamber of the cylinder in a very short time, and the diesel oil forms fine oil particles, which are mixed with high-pressure and high-temperature air, and the combustible mixture burns by itself, which expands violently to generate explosive force, pushing the piston to do work downward. At this time, the temperature can reach 1900-2000℃, and the pressure can reach 60- 100 atmospheric pressure, resulting in great torque.
Traditional diesel engines are characterized by good thermal efficiency and economy. Diesel engines use compressed air to raise the air temperature so that the air temperature exceeds the auto-ignition point of diesel. At this time, diesel, diesel spray and air are simultaneously injected and ignited. Therefore, diesel engines do not need an ignition system.
At the same time, the fuel supply system of diesel engine is relatively simple, so the reliability of diesel engine is better than that of gasoline engine. The high compression ratio of diesel engine is because it is not limited by deflagration and meets the needs of diesel spontaneous combustion.
Thermal efficiency and economy are better than gasoline engines. At the same time, under the same power, the diesel engine has large torque and low speed at the maximum power, which is suitable for trucks.
Reference: Baidu Encyclopedia-Diesel Engine